This invention relates to particulate products useful as aggregate materials in concrete compositions. More particularly, this invention relates to the preparation of high-strength particulate solids and their use in producing concrete compositions having utility in construction and other fields.
Concretes used in a wide variety of construction applications comprise mixtures essentially of solid, relatively inert, particulate materials dispersed or embedded in a matrix of hydrated cementitious binder, such as Portland cement. The inert particulate material, commonly called "aggregate", is usually selected from natural materials such as sand, gravel, and crushed stone, or mixtures of such. Other materials employed as aggregates include slag, cinders, burned clay or shale, etc.
A good aggregate for concrete is one which (a) will form a strong bond between its surface and the surrounding cement paste (or mortar) in the concrete; (b) will not participate in a deleterious reaction with alkali from the cement, and (c) is strong. The strength of the aggregate itself is an important consideration in the ultimate strength of the concrete produced therefrom. There is a continuing need for good aggregate for use in concrete, particularly strong aggregate from readily available and relatively low cost raw materials.